I just had my VMC15's spindle taper reground by Spindle Grinding Service. Very nice people to deal with. My spindle went from 30% contact area and .0001 runout to 96% contact area and <.00005 runout. It would have been 100% but there was a small gouge at the small end of the taper left from a crash by the previous owner. It's a pretty cool process. Their fixture moves up and down with hydraulics and holds a tool post grinder. They turn the machine spindle on and use the y axis to adjust the ammount they are removing. Their grinder does the rest. My spindle was hourglass shaped and it was very easy to see the grinding wheel start to take material off in the middle before the ends. It took about 4 hours for everything. They checked the drawbar pressure before and after, checked the fit by blueing and checked runout with a tool and without. They even checked the drawbar pressure on my new TM-1 for free. It ended up costing $300 plus drive time, and the tech lives 20 minutes from me so that isn't too bad. I haven't tested it yet, but I'm sure there will be a huge improvement.

www.spindlegrinding.com

no affiliation just a happy customer.